Andy Murray vs Serena Williams?
Andy Murray says he would play a match against top women's player Serena Williams after a fan suggested it.
In his latest BBC Sport column he said: "I'd be up for it, why not? How about Las Vegas as a venue?"
Murray reckons people would be interested in watching men play against women to see how the styles match up.
Serena Williams says she is is up for it but added: "I doubt I'd win a point, but that would be fun."
"I think they should mix it up. Everyone says that boys are better. If they mixed it up they would find out that girls are just as good as boys."
Amelia, Flintshire, Wales
"I think women and men should play separately because men are stronger than women so it would be unfair."
Ffion, Wrexham, Wales
"I think there should be more mixed sports because many males think that they are better than females, so it would be great if they could compete against each other."
Alicia, Nottingham, England
"I think it should stay as it is because boys are not physically equal to women."
Tibor, Paris, France
"It would be a great match with a boy against a girl. I think it's unfair that people think boys are better at sports than girls."
"I think it's a great idea to mix up the genders while playing sport. Why not? There is nothing against it. It would show that both genders are able to play sport."
Abbie, Cavan, Ireland
"I think there should be separate girls and boys teams but I think girls and boys should be able to compete against each other."
Noa, New Jersey, America
"It doesn't matter what gender you are, you still can be sporty and win."
Kate, Birmingham, England
"I think that would be amazing! Having mixed teams would be cool because girls don't get as noticed as the boys do! I've always wanted to watch a match like that, especially with Serena and Andy!"
Amelia, Bolton, England
"I think that all sports should be mixed because there are loads more sports that are only for men only."
Harry, Kent, England
"Boys always say that sports like football are just for boys. I think that girls should be mixed with boys."
Aibrean, Tyrone, Northern Ireland
"We think boys already get more attention in sport than girls so it would be a good idea to mix them to give everyone an equal opportunity to have more input."
Class 5HP, Hull, England
"I think it is a great idea. I play football at school and my teacher thinks I play better than some of the boys on the team. I don't think that boys and girls teams should play separately as girls can play just as well as boys at most sports. Just look how well the Arsenal ladies team do. They have won more in the last few years than the men."
Ciara, Kent, England
"I think there should be lots more mixed sport, boys and girls are all the same really! There is no reason why they shouldn't play against each other!"
Megan, Filey, England
"I do think boys and girls should play together because if it's just boys it's boring."
Olivia, Northern Ireland
"Mixed, mixed, mixed! I think it would be great if more sports are mixed because then it would be a lot more exciting and everyone, regardless of sex, would have fairer wages and prize money."
Theo, Reading, England
"I think that there should be more mixed sport because it will give more challenge to sport."
Jack, Grantham, England.
"People say boys are better, but they're not. We are the same. I think it would be good boy versus girl."
Megan, Kent, England.
"I think girls and boys should play together in most sports except rugby and football because they're rough sports and people get injured easily."
Catherine, Nairn, Scotland
"I think there should be more mixed sports because a lot of male athletes think they're better than the female ones.
Alice, Huddersfield, England
"I think in sports like football the teams should be mixed because the girls don't get as noticed as the boys."
Sophie, Cumbria, England